Cyanomethylidene tetrahydroquinoline compounds



United States Patent ABSTRACT OF THE DISCLOSURE Tetrahydroquinoline compounds having two aromatic systems, each of which bears a cyanomethylidine group, at least one of the aromatic systems being a l,2,3,4-tetrahydroquinolin-G-yl group, the two aromatic systems being joined by an ethylenesulfonylethylene group are useful as dyes for hydrophobic textile fibers such as polyester and cellulose acetate fibers.

This invention relates to methine compounds containing the cyanomethylidene group and which are particularly useful as dyes for textile materials such as polyester, cellulose ester, polyamide and acrylic fibers.

The methine compounds have the general formula wherein R and R are the same or different and each represents a phenylene radical including unsubstituted phenylene such as p-phenylene and substituted phenylene such as m-Cl-phenylene in which the chlorine atom is in the position meta to the nitrogen atom, m-(OCH )phenylene o tolylene, 2,5 di(OCH p phenylene, o acetamidop-phenylene etc. The su bstituents attached to the phenylene radical R are not critical and serve primarily as auxochromes to vary the color or shade of the methine compound. Thus, methine compounds very useful as textile dyes are obtained regardless of the type of substituent attached to radical R.

R represents an alkyl radical, that is, lower alkyl and substituted lower alkyl, e.g. methyl, ethyl, butyl, hydroxy lower alkyl, e.g. [i-hydroxyethyl, lower haloalkyl, e.g. fichloroethyl, lower alkoxyalkyl, e.g. 'y-methoxypropyl, lower carboxylic acid acyloxyalkyl, e.g. fi-acetoxyethyl, lower acylamidoalkyl, e.g. 'y-acetamidopropyl, lower cyanoalkyl, e.g. S-cyanoethyl, lower dicarboximidoalkyl, e.g. B-succinimidoethyl, or R represents a benzene radical such as lower alkylphenyl, e.g. p-tolyl, lower alkoxyphenyl, e.g. p-anisyl, halophenyl, e.g. m-chlorophenyl.

The groups m-tolylene See when taken collectively are the same or different and each represents a substituted or unsubstituted tetrahydroquinolin-6-yl radical such as l,2,3,4-tetrahydroquinolin-6-yl, 2,7- dimethyl and 2,2,4,7-tetramethyl-1,2,3,4-tetrahydroquinolin-6-yl.

Z represents either cyano, amide such as CONH or lower carboalkoxyl such as -COOCH COOC3H7 and COOC H CN.

As illustrated in Example 1 below, in the symmetrical compounds contemplated by the formula the and -N-R2 radicals are identical. In the unsymmetrical compounds and are different as shown by Example 4.

Herein, lower alkyl, lower alkylene and the like mean that the carbon chain of the group is a straight or branched-chain of 1 to 4 carbon atoms.

The symmetrical intermediates used in preparing the methine compounds, that is where the groups R and R and groups R and R in the above general formula are the same, are prepared generally by reacting N-substituted anilines or l,2,3,4-tetrahydroquinolines with divinyl sulfone in the presence of a little acetic acid. This reaction is illustrated as follows:

where R and R correspond to the groups in the above general formula. An alternate method for the preparation of the compounds where R is phenyl or substituted phenyl is to react the corresponding primary amine with divinyl sulfone to give the his compound and then to alkylate this intermediate.

The unsymmetrical intermediates, that is where the groups R and R and/ or the groups R and R are different, may be prepared by reacting one equivalent of the aromatic amine with one equivalent (or an excess) of divinyl sulfone to give the N-2-(vinylsulfonyl)ethyl intermediate which may be reacted with another equivalent of amine. This may be illustrated by the following reaction:

where R, R R and R correspond to the groups in the above general formula, but where the groups R and R and/or the groups R and R are different. The resulting intermediates are then converted to the bis-aldehydes by reaction'with POCl and dimethylformamide, following which the bis-aldehydes are reacted with nitriles containing an active methylene group of formula NCCH -Z such as malononitrile or alkylcyanoacetates such as methylcyanoacetate to yield the desired compounds containing the cyanomethylidene group.

The methine compounds can be used for dyeing textile materials including synthetic polymer fibers, yarns and fabrics giving fast brilliant yellow shades when applied by conventional dyeing methods to polyesther fibers. The methine compounds also have good afiinity for cellulose ester and polyamide fibers. When the methine compounds are used for dyeing such hydrophobic materials, they should be free of water-solubilizing groups such as sulfo and carboxyl groups. In general, the dyes have good fastness, for example, to light, washing, gas (atmospheric fumes) and sublimation.

The following examples will serve to illustrate the preparation of representative methine compounds and intermediates of our invention.

EXAMPLE 1 A. Preparation of bis[2-(N-ethyl-m-toluidino) ethyl] sulfone 27.0 g. of N-ethyl-m-toluidine, 1 1.8 g. divinylsulfon'e, 5 cc. glacial acetic acid, and 50 cc. toluene were refluxed together for 24 hr. The toluene and acetic acid were removed under vacuum and the residue taken up in 150 ml. of hot alcohol. This solution was chilled for 2 hrs. at near C. and the white crystalline product collected by filtration. Yield2'1.4 g., M.P. 58-61 C. A sample recrystallized once from alcohol melted at 65-67 C.

B. Preparation of the bis-aldehyde from 1A l l o In 0 it.

C. Preparation of the dye 2.22 g. of the product from B above, 0.66 g. malononitrile, 3 drops piperidine, and 35 cc. alcohol were refluxed together for 1 hr. The mixture was allowed to cool to room temperature. The yellow dye was collected by filtration, washed with a little alcohol, and dried in air. Yield-2.3 g., M.P. l60-162 C. This dye has the following structures NC C211 2 5 It dyes polyester and cellulose acetate fabrics in bright yellow shades of outstanding fastness properties.

EXAMPLE 2 A. Preparation of bis[2-(N-Z-hydroxyethyl-m-toluidine) ethyl] sulfone 30.2 g. N-2-hydroxyethyl-m-toluidine, 11.8 g. divinyl sulfone, cc. acetic acid, and 50 cc. toluene were refluxed together for 24 hr. The toluene and acetic acid were removed under vacuum to leave a quantitative yield of the product, which was a viscous oil.

B. Preparation of 4,4'-sulfonylbis(ethylene-N-2- chloroethylimino)-o-tolualdehyde C. Preparation of the dye from 213 2.56 g. of the above aldehyde (23), 0.66 g. malononitrile, 3 drops piperidine, and 25 cc. alcohol were refluxed together for 1 hr. The mixture was allowed to cool to room temperature and filtered. It dyes polyester fibers, cellulose acetate, and Verel modacrylic bright yellow shades of excellent fastness.

EXAMPLE 3' A. Preparation of bis[ 2-(m-toluidino)ethylJsulfone 42.8 g. m-toluidinc, 1 1.8 g. divinylsulfone, 5 cc. acetic acid, and .110 ml. toluene were refluxed together for 24 hr. The toluene and excess m-toluidine were removed under reduced pressure. The residue was taken up in 150 ml. of alcohol and on cooling this solution a white solid was obtained, which was collected by filtration and dried in air. Yield25.5 g., M.P. 8 285 C. A sample of this product recrystallized from alcohol melted at 87-88.5 C.

B. Preparation of bis 2-(N-2-cyanoethyl-m-tolhidino) ethyl sulfone 10 g. bis 2-(m-toluidino)ethyl sulfone, 5 cc. acetic acid, 5 cc. acrylonitrile, 0.5 g. cupric acetate monohydrate, and 1.0 g. copper bronze were heated together in an autoclave at 150 C. for 10 hr. The mixture was filtered and the acetic acid and excess acrylonitrile removed under vacuum. The product was a dark viscous oil, yield13.0 g. The product had the following structure:

(IJZILCN (IIzHrCN Q-N-CzlIaSOzCzHr-N I 1 CH3 CH3 C and D The aldehyde and the dye were prepared by using the same procedures as given in IE and 1C above. This dye had the following structure:

c it on N G $1114 0 N 2 4 l C N c=1rc--N-ozrnsozoinn r on=o NC \CN on. on.

EXAMPLE 4 A. Preparation of 2,2,4,7-tetran1ethyl-1-(2-vinylsulfonyl) ethyl-l,2,3,4-tetrahydroquinoline 37.8 g. 2,2,4,7-tetran1ethyl-1,2,3,4-tetrahydroquinoline in 50 cc. toluene was added dropwise to a refluxing solu tion of 25.9 g. divinylsulfone, and 5 cc. acetic acid in 50 cc. toluene over a period of 20 minutes. After refluxing 24 hr., the solvent was removed under vacuum and the unreacted starting materials distilled. There was obtained about 38 g. of material boiling at 71-117 C. at 1.1/1.5 mm. Hg. The distillation was discontinued and the residue taken up in ml. of hot alcohol. The de- 5 sired product separated out as a White solid on cooling, which was filtered, washed with a little alcohol and dried r in air. Yield22 g., M.P. 109112 C. This material has the following structure:

H CH3 Q U C 3 a) 2 Jh AS OaCH=C 2 B. Preparation of 1-ethylene-tetrahydro-2,2,4,7-tetramethyl-1-quinolyl-N-ethylene-N-ethyl-m-toluidine sulfone 6.22 g. of the product from 4A above, 5.40 g. of N- ethyl-m-toluidine, 2 cc. acetic acid, and 50 cc. toluene were refluxed together for 24 hr. The solvent was removed under vacuum and the excess N-ethyl-m-toluidine distilled to give a very viscous residue which could not be made to crystallize. Yield8.7 g. This material had the following structure:

C. Preparation of the bis-aldehyde from material prepared in 4B above D. Preparation of the dye 2.44 g. bis-aldehyde from 4B above, 0.66 g. malononitrile, 5 drops piperdine, 50 ml. alcohol were refluxed together for 1 hr. On cooling to room temperature an orange solid resulted, which was collected by filtration, washed with a little alcohol, and dried in air. Yield2.0 g., M.P. 130-135 C. One recrystallization from alcohol 6 increased the MP. to 140-143 C. This unsymmetrical dye has the following structure:

CH; \N (CH3)2 CzH5 I ON CH3 EXAMPLE 5 A. Preparation of N-ethyl-N-(2-vinylsulfonyl)ethyl-mtoluidine 27.0 g. N-ethyl-m-toluidine, 23.6 g. divinylsulfone, 5 cc. glacial acetic acid, and ml. of toluene were refluxed together for 12 hr. The product was distilled under reduced presure. Yield25.6 g., B.P. 157-159 C. at 0.35 mm. Hg, n l.5607.

B. Preparation of l-ethylene-tetrahydro-7-methyl-1- quinolyl-N ethylene-N-ethyl-m-toluidine sulfone 25.3 g. N-ethyl-N-(Z -vinylsulfonyl)ethyl-m-toluidine, 29.4 g. 7-methyl-l,2,3,4-tetrahydroquinoline, 10 cc. glacial acetic acid, and 200 cc. toluene were refluxed together for 24 hr. The toluene and excess 7-methyl-l,2,3,4-tetrahydroquinoline were removed under vacuum to yield 40 g. of product, which did not crystallize. It had the following structure:

C. and D. The preparation of the aldehyde and the dye was carried out as in IE and 1C above The unsymmetrical dye had the following structure:

The intermediates for the following Examples 6-24 listed in Table I were prepared as in Examples 1A, 1B, or 3A and 3B. The aldehydes were prepared by the methods illustrated in Examples 1B and 2B. The dyes were made as in Example 10. The dyes had the structures indicated in the table, referring to the general formula at the beginning of this specification, and dye polyesters to bright yellow shades.

TABLE I (SYMMETRICAL DYES) Preparative Ex. No. R and R2 R1 and Rs Z method of Intermediate 6 Phenyleue C2II5 -CN 1A. 7 m-Tolylene -CH3 CN 1A.

(H) s .do .Q-CHa CNH2 1A.

0 ll 9 do -C4Ho(l1) '0CI{3 1A.

(H) 10 "d0 --C2H5 -COCH2CH(CH3)2 1A.

11--. Phenylene C2H4Cl -CN 1A. 12.-. "do CzH4CN CN 3A and 3B. 13 m-Chlorophenylene --C2H4CN -CN 3A and 3B. 14 Tetrahydroquinoline Part of ring -CN 1A. 15 2,7-dlmethyltetrahydroquinoline. Part of ring CN 1A.

Preparative Ex. No. R and R2 R1 and It; Z method of Intermediate 16 7 metl1yltetrahydroquinoline Part of ring CN 1A. 17-. m-OCH phenylene CQH5 CN 1A. 18 do Cal'ls CN 1A. l9 o-Tolylcnlxn C2H5 CN 1A. 20 m-Tolylone cnnoCI-h CN 1A.

I 21 d C2H4NH(.|)CH3 CN 1A.

22 d0 "C2H-1N CN 1A.

if 23 r Phenylene C2H4OCCH3 CN 1A.

24 m-Acetylaminophenylene CzH CN 1A.

Unsymmetrical methine compounds were prepared by EXAMPLE 38 the methods of Examples 4A-D and 5A-D and have the 256 4,42 [sulfonylbis ethylen e N 2 Ch1Omethy1imi formulas shown in the following Table II, referring to the 25 no 0 to1ua1dehyde, 141 g. isobutyl cyanoacetate 5 above general formula, and y P yester fabrics to fast drops piperidine, and 25 ml. ethanol were refluxed tobright yellow shades. gether for 1 hour. After allowing to cool, the yellow crys- TABLE II (UNSYMMETRICAL DYES) Ex. No. R R1 R2 R3 Z 25 Phonylene e C2H5 CzH CN m-T0lylcnc C2H C4Hg(l1) CN Phenylenc C2H4C1 CzI'LlOLN CN 1, 2, 3. 4-tetrahydroquinoline part of a r1ng d C2H5 CNH2 ol ..d0 Phenylene. CH3 C-OCH;

2, 7-di1nethyl-tetrahydroquinoline do m-Methoxy phenylene. C2H CN 2,2,4,7-tetramethyl tctrahydroquinoline. do. 7-metl1yltotrahydroquinoline. Part of a CN do 2, 7-din1ethyltetral1ydroquinoline do. .i CN H mChloropl1enyleue C2H5 CN H (phcnyl) Phenylene v. C2H4OCH3" CN cyclohexyl m-Tolylene. C-H4Cl.... CN 4methoxyphenyl "do CzHs CN The following examples further illustrate the synthesis tals were collected by filtration, washed with ethanol and of the methine compounds of the invention. air dried. There was obtained 2.8 g. of dye which dyed cellulose acetate and polyester fibers bright shades of EXAMPLE 37 yellow. It had the following structure: 1.11 g. 4,4-[sulfonylbis(ethylene-N-ethylimino)]di-0 on oncmoc coon OH on.

3 2 n on. on. g

tolualdehyde, 0.50 g. methyl cyanoacetate, 3 drops piperidine, and ml. ethanol were refluxed together for 1 EXAMPLE 39 hour. The reaction mixture was allowed to cool and the 2.44 g. tetrahydro-Z,2,4,7-tetramethyl 1-{2-[2-(4-forproduct collected by filtration, washed with ethanol and 55 myl-N-ethyl-m-toluidino)ethylsulfonyl1ethyl} 6 quinoair dried. There was obtained 1.3 g. of yellow dye havline-carboxaldehyde [from Example 4C], 1.38 g. 2-

ing the following structure: (cyanoethyl)cyanoacetate, 5 drops piperidine, and ml.

CqHz, NC 02115 1 CN I /C=HO NCgI 4SO7CgH4N CH=C\ 01130-0 0-0611; ([5 CH3 CH3 (I5 6 ethanol were reacted and worked up exactly as in Example 36 to give a yellow dye of the following structure:

9 EXAMPLE 40 4,4-[sulfonylbis (ethylene-N-ethylimino)]di o tolualdehyde (1.11 g), 2-cyanoacetamide (0.42 g.), 3 drops piperidine, and ml. ethanol were refluxed together for 10 polyamides which can be dyed with the methine compounds.

The invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modione hour. The product was collected, washed, and dried. 5 fications can be effected within the spirit and scope of the This material dyed cellulose acetate and polyester fibers invention as described hereinabove, and as defined in the bright yellow shades and had the following structure: appended claims.

NC CrHr crHr CN O=H C -I ICrH4SO2C zHJkQ-C H=C fi G (EH3 CH3 E]: NH,

The methine compounds of the invention may be used What we claim is: for dyeing hydrophobic fibers such as linear polyester, 1. A methine compound having the formula cellulose ester, acrylic, polyamide, etc., fibers in the manner described in Us. Patents 2,880,050, 2,757,064, 2,782,- 187 and 3,043,827. The following example illustrates 20HrS rGHrGHr-N-RrCH=O methods by which the methine compounds of the inven- Z tion can be used to dye-textile materials. I

0.1 gram of the dye is dissolved in the dye pot by warm- Wherfim ing in 5 cc. of ethylene glycol monomethyl ether. A 2% P'Phenylene group; lgcpon T and 05% Sodium lign-m sulfonate aqueous 1 and 'R are the same or dilferent and each 1s a lower solution is added, with stirring, until a fine emulsion is alkyl group phenyl or phenyl Substltuted with obtained. Water is then slowly added to a total volume of er alkyl lower alkoxy or halogen; 200 cc. Three cc. of Dacronyx (a chlorinated benzene R1 R3 emulsion) are added and 10 grams of a textile fabric made i; and i of Kodel polyester fibers are entered. The fabric is worked 10 minutes without heat and then for 10 minutes at h i collecnvelya are the g dlfierent 80 C. The dyebath is then brought to the boil and held an 9 gepresents a r 3, ydroqumolm--yl at the boil for one hour. Following this, the fabric is rinsed Z an in warm water, then scoured in an aqueous 0.2% soda-ash 1S cyano solution. After scouring, the fabric is rinsed with water f and dried. Accordingly, since the methine compounds of the invention are water-insoluble, they can be applied or lower carbalkoxy from aqueous dispersions in the manner of the so-called 2 A methine compougld accordin to claim 1 wherein dispersed dyes. However, coloration can also be efis p phenylene group; g fected f example. by mcorporatmg methme R is lower alkyl or lower alkyl substituted with cyano, Pounds mto the ipmnmg dope and spmmilg i fiber as halogen, lower alkoxy hydroxy or lower carboxylic usual. The methine compounds of our invention have acid acyloxy varying utility as dyes. The degree of utility varies, for example, depending upon the material being dyed and the formula of the methine compound. Thus, for example, all NR3 the dyes will not have the same degree of utility for the collectively are a 1,2,3}; tetrahydroquinolin 6 yl same material. grou and Cellulose esters which can be dyed with the 1methine Z is cyaIm compounds include cellulose aliphatic carboxy ic acid esters having 2 to 4 carbon atoms in the acid groups 3. A methine compound according to claim 1 wherein thereof, by which we mean to include, for example, both partially hydrolyzed and unhydrolyzed cellulose acetate, R and cellulose propionate and cellulose acetate-butyrate. 5

Polymeric linear polyester materials of the terephthalate g t, i s fiiigg l i r ii i aif are a 1,234 tetrahy type are illustrative of the linear aromatic polyester tex- Z is c g tile materials that can be dyed with the new methine com- 4 A d h d h h f pounds of our invention. The terephthalate fibers sold e y e avmgt e ormula under the trademarks Kodel, Dacron and Terylene, Rr for example, in the form of filaments, yarn and fabric, for OHC R N CH CH sO CH H iq example, are illustrative of the polyester textile materials wherein that can be dyed. Kodel polyester fibers are more particularly described in US. Patent 2,901,446. Dacron and R is a p-p y g p; Terylene polyester fibers are described, for example, in R is a lower alkyl group, phenyl, or phenyl substituted US. Patent 2,465,319. The polymeric linear polyester with lower alkyl, lower alkoxy, or halogen; and materials disclosed in US. Patents 2,945,010, 2,957,745 R1 R3 and 2,989,363, for example, can be dyed. The linear aromatic polyester materials specifically named have a meltand ing point of at least 200 C. when taken collectively, are the same or different Nylon, in fiber, yarn and fabric form is representative of and each is a 1,2,3,4-tetrahydroquinolin-G-yl group. 

